What are the Different Masses of the Planets? - Universe Today Universe Today What are the Different Masses of the Planets? Article Updated: 22 Jul , 2016 by Matt Williams It is a well known fact that the planets of the Solar System vary considerably in terms of size. For instance, the planets of the inner Solar System are smaller and denser than the gas/ice giants of the outer Solar System . And in some cases, planets can actually be smaller than the largest moons. But a planet’s size is not necessarily proportional to its mass. In the end, how massive a planet is has more to do with its composition and density. So while a planet like Mercury may be smaller in size than Jupiter’s moon Ganymede or Saturn’s moon Titan , it is more than twice as massive than they are. And while Jupiter is 318 times as massive as Earth, its composition and density mean that it is only 11.21 times Earth’s size. Let’s go over the planet’s one by one and see just how massive they are, shall we?

Mercury: Mercury is the Solar System’s smallest planet, with an average diameter of 4879 km (3031.67 mi). It is also one of its densest at 5.427 g/cm3, which is second only to Earth. As a terrestrial planet , it is composed of silicate rock and minerals and is differentiated between an iron core and a silicate mantle and crust. But unlike its peers (Venus, Earth and Mars), it has an abnormally large metallic core relative to its crust and mantle. All told, Mercury’s mass is approximately 0.330 x 1024 kg, which works out to 330,000,000 trillion metric tons (or the equivalent of 0.055 Earths). Combined with its density and size, Mercury has a surface gravity of 3.7 m/s² (or 0.38 g). Internal structure of Mercury: 1. Crust: 100–300 km thick 2. Mantle: 600 km thick 3. Core: 1,800 km radius.

Credit: MASA/JPL Venus: Venus , otherwise known as “Earth’s Sister Planet”, is so-named because of its similarities in composition, size, and mass to our own. Like Earth, Mercury and Mars, it is a terrestrial planet, and hence quite dense. In fact, with a density of 5.243 g/cm³, it is the third densest planet in the Solar System (behind Earth and Mercury). Its average radius is roughly 6,050 km (3759.3 mi), which is the equivalent of 0.95 Earths. And when it comes to mass, the planet weighs in at a hefty 4.87 x 1024 kg, or 4,870,000,000 trillion metric tons. Not surprisingly, this is the equivalent of 0.815 Earths, making it the second most massive terrestrial planet in the Solar System. Combined with its density and size, this means that Venus also has comparable gravity to Earth – roughly 8.87 m/s², or 0.9 g.

Earth: Like the other planets of the inner Solar System, Earth is also a terrestrial planet, composed of metals and silicate rocks differentiated between an iron core and a silicate mantle and crust. Of the terrestrial planets, it is the largest and densest, with an average radius of 6,371.0 km (3,958.8 mi) and a mean of density of 5.514 g/cm3. The Earth’s layers, showing the Inner and Outer Core, the Mantle, and Crust. Credit: discovermagazine.com And at 5.97 x 1024 kg (which works out to 5,970,000,000,000 trillion metric tons) Earth is the most massive of all the terrestrial planets. Combined with its size and density, Earth experiences the surface gravity that we are all familiar with – 9.8 m/s², or 1 g. Mars: Mars is the third largest terrestrial planet, and the second smallest planet in our Solar System. Like the others, it is composed of metals and silicate rocks that are differentiated between a iron core and a silicate mantle and crust.

But while it is roughly half the size of Earth (with a mean diameter of 6792 km, or 4220.35 mi), it is only one-tenth as massive. In short, Mars has a mass of 0.642 x1024 kg, which works out to 642,000,000 trillion metric tons, or roughly 0.11 the mass of Earth. Combined with its size and density – 3.9335 g/cm³ (which is roughly 0.71 times that of Earth’s) – Mars has a surface gravity of 3.711 m/s² (or 0.376 g). Jupiter: Jupiter is the largest planet in the Solar System. With a mean diameter of 142,984 km, it is big enough to fit all the other planets (except Saturn) inside itself, and big enough to fit Earth 11.8 times over.

But with a mass of 1898 x 1024 kg (or 1,898,000,000,000 trillion metric tons), Jupiter is more massive than all the other planets in the Solar System combined – 2.5 times more massive, to be exact. Jupiter’s structure and composition. (Image Credit: Kelvinsong CC by S.A. 3.0) However, as a gas giant, it has a lower overall density than the terrestrial planets. It’s mean density is 1.326 g/cm, but this increases considerably the further one ventures towards the core. And though Jupiter does not have a true surface, if one were to position themselves within its atmosphere where the pressure is the same as Earth’s at sea level (1 bar), they would experience a gravitational pull of 24.79 m/s2 (2.528 g). Saturn: Saturn is the second largest of the gas giants; with a mean diameter of 120,536 km, it is just slightly smaller than Jupiter.

However, it is significantly less massive than its Jovian cousin, with a mass of 569 x 1024 kg (or 569,000,000,000 trillion metric tons). Still, this makes Saturn the second most-massive planet in the Solar System, with 95 times the mass of Earth. Much like Jupiter, Saturn has a low mean density due to its composition. In fact, with an average density of 0.687 g/cm³, Saturn is the only planet in the Solar System that is less dense than water (1 g/cm³). But of course, like all gas giants, its density increases considerably the further one ventures towards the core. Combined with its size and mass, Saturn has a “surface” gravity that is just slightly higher than Earth’s – 10.44 m/s², or 1.065 g. Diagram of Saturn’s interior. Credit: Kelvinsong/Wikipedia Commons Uranus: With a mean diameter of 51,118 km, Uranus is the third largest planet in the Solar System.

But with a mass of 86.8 x 1024 kg (86,800,000,000 trillion metric tons) it is the fourth most massive – which is 14.5 times the mass of Earth. This is due to its mean density of 1.271 g/cm3, which is about three quarters of what Neptune’s is. Between its size, mass, and density, Uranus’ gravity works out to 8.69 m/s2, which is 0.886 g. Neptune: Neptune is significantly larger than Earth; at 49,528 km, it is about four times Earth’s size. And with a mass of 102 x 1024 kg (or 102,000,000,000 trillion metric tons) it is also more massive – about 17 times more to be exact. This makes Neptune the third most massive planet in the Solar System; while its density is the greatest of any gas giant (1.638 g/cm3).

Combined, this works out to a “surface” gravity of 11.15 m/s2 (1.14 g). As you can see, the planets of the Solar System range considerably in terms of mass. But when you factor in their variations in density, you can see how a planets mass is not always proportionate to its size. In short, while some planets may be a few times larger than others, they are can have many, many times more mass. For more information, check out Nine Planets overview of the Solar System, NASA’s Solar System Exploration , and use this site to find out what you would weigh on other planets . Astronomy Cast has episodes on all of the planets. Here’s Episode 49: Mercury to start! Share this: How Big is Jupiter? How Big is Jupiter? By Nola Taylor Redd, Space.com Contributor | November 7, 2012 06:24pm ET MORE The largest planet in the solar system, the gas giant Jupiter is approximately 318 times as massive as Earth. If the mass of all of the other planets in the solar system were combined into one "super planet," Jupiter would still be two and a half times as large.

Jupiter is the largest planet in the solar system. Credit: NASA Radius, diameter and circumference Jupiter has a mean radius of 43,440.7 miles (69,911 kilometers), about a tenth that of the sun. However, its rapid rotation — it spins once every 9.8 hours — causes it to bulge at the equator, where the diameter is 88,846 miles (142,984 km). In contrast, the diameter at the poles is only 83,082 miles (133,708 km). This stretched shape is known as an oblate spheroid. If you were to walk around the equator of Jupiter, you would travel 272,946 miles (439,264 km), over 10 times the distance around Earth's center line. Because Jupiter is made of gas , mostly, its surface is considered uniform. As such, it lacks high and low points — mountains and valleys — such as those found on rocky terrestrial planets. Density, mass and volume Known as a gas giant, Jupiter is composed primarily of hydrogen and helium.

It weighs in at 1.9 x 1027 kilograms. Although it is significantly more massive than Earth, it is only a fifth as dense, at 1,326g/cm3, because it is made of gas rather than rock. The volume of Jupiter is 1,431,281,810,739,360 cubic kilometers, 1,321 times that of Earth. The surface area of this enormous planet is 23,713,907,537 square miles, or 6.1419x1010 square kilometers, 120 times that of our planet. Jupiter's structure resembles that of the sun, but would need to be 75 times its present mass to undergo the fusion of hydrogen that fuels a star. The mass of the largest gas giant planets found outside of the solar system is often given in terms of the enormous planet.

— Nola Taylor Redd, SPACE.com Contributor Related: Planet X or Nibiru is headed for Earth, doomsayers believe - NY Daily News Planet X, or Nibiru, is on a crash course with Earth, doomsayers believe — prophecies draw new focus with 'Planet Nine' discovery Planet X or Nibiru is headed for Earth, doomsayers believe Thursday, January 21, 2016, 2:21 PM It's the end of the world as we know it. Doomsayers have prophesized for decades about a giant, rogue planet in our solar system — dubbed Planet X or Nibiru — that has the capability of colliding or passing near Earth, with catastrophic consequences. And of course, NASA has known about the mystery planet for years, but declined to warn us. Doomsayers have prophesized for decades about a giant, rogue planet in our solar system that has the capability of colliding or passing near earth.

((c) Sdecoret | Dreamstime.com) While many of the theories, hoaxes and conspiracies about Planet X have been debunked, the beliefs gained new attention with Wednesday's announcement that a new planet — "Planet Nine" — has been discovered in our solar system. A new planet, "Planet Nine," has been discovered in our solar system. (HO/AFP/Getty Images) The planet, according to Caltech researchers, has a mass about 10 times that of Earth and takes about 15,000 years to make a full orbit around the sun. Could "Planet Nine" actually be the Planet X we’ve been waiting for? Here's a look at the mythology, history and conspiracies surrounding the concept of Planet X. Fueling our cosmic wonder Astronomer Percival Lowell searched for Planet X in the early 1900s. (J.E. Purdy/© CORBIS) Astronomer Percival Lowell kicked off the search for Planet X in the early 1900s by predicting a planet beyond Neptune. He spent years studying the night sky from his observatory in Flagstaff, Ariz., looking for the mysterious planet.

His calculations helped astronomers find Pluto in 1930. Lowell's beliefs about Planet X, while largely disproven, shaped the public's perceptions about space, and fueled our cosmic wonder. Nibiru explained Soviet-born Zecharia Sitchin first wrote about Nibiru — a distant member of our solar system — in the 1970s. The name comes from Babylonian astrology, and relates to astronomical objects. Sitchin was a scholar who interpreted ancient texts and biblical writings. His books have sold millions of copies. According to Sitchin, Nibiru features an elongated, elliptical orbit and comes near Earth every 3,600 years. Zecharia Sitchin said that inhabitants of the planet Nibiru came to Earth about 400,000 years ago and created humans. (ZeroEightyFour via YouTube) Ancient astronauts from the mysterious planet visited Earth about 400,000 years ago and genetically engineered the inhabitants — creating humans, according to Sitchin. Despite Sitchin's death in 2010, his website is still maintained, and a Wednesday post addressed the discovery of a new planet.

"With an elliptical orbit of 10,000 or 20,000 of our years, this planet may not be Nibiru, which has an orbit of about 3,600 of our years," a post on his website states. "However, this prediction of a likely additional planet in our solar system is exciting news. Perhaps the search will lead us to either finding Nibiru, or perhaps we'll find that something has changed and impacted Nibiru's orbit since the last time it orbited Earth." Web of concern Wisconsin resident Nancy Lieder put forward the idea about the Nibiru Cataclysm in the mid-1990s, after claiming she had the ability to receive messages from aliens in the Zeta Reticuli star system. Lieder wrote about the supposed deadly encounter — either a collision or near-miss — between Earth and Planet X on the website ZetaTalk. In this so-called encounter, the mysterious planet's intense gravitational pull would create mass destruction on earth.

She initially stated that Planet X was going to arrive in 2003, but she later wrote that the date was a "white lie." Lieder and ZetaTalk have declined to give further dates for Planet X’s return, but "watching the Earth changes, and the behavior of those in the corridors of power, will be the best clues." The calendar shifts After the world didn't end in 2003, the doomsday date was moved to 2012, linking with the end of the Mayan calendar. According to the theories, Nibiru was slated to crash into Earth on Dec. 21, the winter solstice. As the date approached, NASA faced more and more questions about Planet X. "While this is a joke to some people and a mystery to others, there is a core of people who are truly concerned," David Morrison, an astrobiologist at NASA Ames Research Center, said at the time. After the world kept spinning after 2003, some believed Nibiru would crash into Earth in 2012, linking to the end of the Mayan calendar.

(Israel Leal/AP) The early 1980s were evidently an important time in the search for Planet X. The "experts" state that two NASA scientists sighted a Jupiter-sized object — Planet X — in 1983. Additionally, a 1984 Associated Press article claims that dinosaurs and other species were killed off by a dim dwarf star that periodically causes immense comet showers, "plunging Earth into cold and darkness that kills up to 70 percent of all life." The NASA "sighting" was later debunked — no, sorry, it never happened — and the dwarf star theory was also disproven, but they still offer fodder for Planet X enthusiasts. A dwarf planet discovered Eris, an actual dwarf planet, was first observed in 2003. The planet is located beyond Neptune, and larger than Pluto — the second largest dwarf planet known in the Solar System. According to NASA, the closest Eris can come to Earth is about four billion miles. 'Doomsday' comet The Internet churned up a new focus for Planet X in 2011: the comet Elenin, following earthquakes in Japan and Chile.

After scientists voiced their concerns — namely, that comets don't have magnetic fields — conspiracy theorists speculated that the comet could have been Nibiru in disguise. The "doomsday" comet eventually broke apart when it passed close to the sun. Comet Elenin posed no threat to Earth in 2011. (NASA) Christmas Eve Asteroid A “Christmas Eve Asteroid” sparked similar online chatter in 2015, but missed Earth by about 6.8 million miles. “It's nothing to worry about,” scientists with NASA’s Jet Propulsion Laboratory wrote at the time. “Crossing the street, driving a car are far more dangerous to individuals on a daily basis.” NASA’s response NASA scientists have emphasized for years that Nibiru doesn’t exist. If a planet were heading to Earth, astronomers would have been tracking the object for at least a decade, NASA has stated. In Popular Culture The lingering hoax has brought Planet X attention in popular culture.

The doomsday movie “2012” featured a viral marketing campaign centered around “a mysterious celestial body” entering Earth’s orbit, “with disastrous consequences.” The 2013 movie "Star Trek Into Darkness" shows Kirk and McCoy running through Nibiru's red forest. (Star Trek Into Darkness) The 2013 movie "Star Trek Into Darkness" shows Kirk and McCoy running through Nibiru's red forest before leaping off a cliff. The planet was also discussed on "Scooby-Doo! Mystery Incorporated." Tags: Jupiter - Educational facts and history of the planet Jupiter. Jupiter News Jupiter Facts Jupiter is the fifth planet from the Sun and by far the largest. Jupiter is more than twice as massive as all the other planets combined (the mass of Jupiter is 318 times that of Earth). Planet Profile orbit : 778,330,000 km (5.20 AU ) from Sun diameter : 142,984 km (equatorial) mass : 1.900e27 kg History of Jupiter Jupiter (a.k.a.

Jove; Greek Zeus ) was the King of the Gods, the ruler of Olympus and the patron of the Roman state. Zeus was the son of Cronus (Saturn). Jupiter is the fourth brightest object in the sky (after the Sun , the Moon and Venus ). It has been known since prehistoric times as a bright "wandering star". But in 1610 when Galileo first pointed a telescope at the sky he discovered Jupiter's four large moons Io , Europa , Ganymede and Callisto (now known as the Galilean moons) and recorded their motions back and forth around Jupiter. This was the first discovery of a center of motion not apparently centered on the Earth. It was a major point in favor of Copernicus 's heliocentric theory of the motions of the planets (along with other new evidence from his telescope: the phases of Venus and the mountains on the Moon ). Galileo's outspoken support of the Copernican theory got him in trouble with the Inquisition . Today anyone can repeat Galileo's observations (without fear of retribution :-) using binoculars or an inexpensive telescope.

Jupiter was first visited by Pioneer 10 in 1973 and later by Pioneer 11 , Voyager 1 , Voyager 2 and Ulysses . The spacecraft Galileo orbited Jupiter for eight years. It is still regularly observed by the Hubble Space Telescope . The gas planets do not have solid surfaces, their gaseous material simply gets denser with depth (the radii and diameters quoted for the planets are for levels corresponding to a pressure of 1 atmosphere). What we see when looking at these planets is the tops of clouds high in their atmospheres (slightly above the 1 atmosphere level). Jupiter is about 90% hydrogen and 10% helium (by numbers of atoms, 75/25% by mass) with traces of methane, water, ammonia and "rock". This is very close to the composition of the primordial Solar Nebula from which the entire solar system was formed. Saturn has a similar composition, but Uranus and Neptune have much less hydrogen and helium. Our knowledge of the interior of Jupiter (and the other gas planets) is highly indirect and likely to remain so for some time.

(The data from Galileo 's atmospheric probe goes down only about 150 km below the cloud tops.) Jupiter probably has a core of rocky material amounting to something like 10 to 15 Earth-masses. Above the core lies the main bulk of the planet in the form of liquid metallic hydrogen. This exotic form of the most common of elements is possible only at pressures exceeding 4 million bars , as is the case in the interior of Jupiter (and Saturn). Liquid metallic hydrogen consists of ionized protons and electrons (like the interior of the Sun but at a far lower temperature). At the temperature and pressure of Jupiter's interior hydrogen is a liquid, not a gas. It is an electrical conductor and the source of Jupiter's magnetic field. This layer probably also contains some helium and traces of various " ices ". The outermost layer is composed primarily of ordinary molecular hydrogen and helium which is liquid in the interior and gaseous further out. The atmosphere we see is just the very top of this deep layer. Water, carbon dioxide, methane and other simple molecules are also present in tiny amounts. Recent experiments have shown that hydrogen does not change phase suddenly.

Therefore the interiors of the jovian planets probably have indistinct boundaries between their various interior layers. Three distinct layers of clouds are believed to exist consisting of ammonia ice, ammonium hydrosulfide and a mixture of ice and water. However, the preliminary results from the Galileo probe show only faint indications of clouds (one instrument seems to have detected the topmost layer while another may have seen the second). But the probe's entry point (left) was unusual -- Earth-based telescopic observations and more recent observations by the Galileo orbiter suggest that the probe entry site may well have been one of the warmest and least cloudy areas on Jupiter at that time. Data from the Galileo atmospheric probe also indicate that there is much less water than expected. The expectation was that Jupiter's atmosphere would contain about twice the amount of oxygen (combined with the abundant hydrogen to make water) as the Sun. But it now appears that the actual concentration much less than the Sun's. Also surprising was the high temperature and density of the uppermost parts of the atmosphere. Jupiter and the other gas planets have high velocity winds which are confined in wide bands of latitude. The winds blow in opposite directions in adjacent bands.

Slight chemical and temperature differences between these bands are responsible for the colored bands that dominate the planet's appearance. The light colored bands are called zones; the dark ones belts. The bands have been known for some time on Jupiter, but the complex vortices in the boundary regions between the bands were first seen by Voyager. The data from the Galileo probe indicate that the winds are even faster than expected (more than 400 mph) and extend down into as far as the probe was able to observe; they may extend down thousands of kilometers into the interior. Jupiter's atmosphere was also found to be quite turbulent. This indicates that Jupiter's winds are driven in large part by its internal heat rather than from solar input as on Earth. The vivid colors seen in Jupiter's clouds are probably the result of subtle chemical reactions of the trace elements in Jupiter's atmosphere, perhaps involving sulfur whose compounds take on a wide variety of colors, but the details are unknown. The colors correlate with the cloud's altitude: blue lowest, followed by browns and whites, with reds highest. Sometimes we see the lower layers through holes in the upper ones.

The Great Red Spot (GRS) has been seen by Earthly observers for more than 300 years (its discovery is usually attributed to Cassini , or Robert Hooke in the 17th century). The GRS is an oval about 12,000 by 25,000 km, big enough to hold two Earths. Other smaller but similar spots have been known for decades. Infrared observations and the direction of its rotation indicate that the GRS is a high-pressure region whose cloud tops are significantly higher and colder than the surrounding regions. Similar structures have been seen on Saturn and Neptune . It is not known how such structures can persist for so long. Jupiter radiates more energy into space than it receives from the Sun. The interior of Jupiter is hot: the core is probably about 20,000 K. The heat is generated by the Kelvin-Helmholtz mechanism, the slow gravitational compression of the planet.

(Jupiter does NOT produce energy by nuclear fusion as in the Sun; it is much too small and hence its interior is too cool to ignite nuclear reactions.) This interior heat probably causes convection deep within Jupiter's liquid layers and is probably responsible for the complex motions we see in the cloud tops. Saturn and Neptune are similar to Jupiter in this respect, but oddly, Uranus is not. Jupiter is just about as large in diameter as a gas planet can be. If more material were to be added, it would be compressed by gravity such that the overall radius would increase only slightly. A star can be larger only because of its internal (nuclear) heat source. (But Jupiter would have to be at least 80 times more massive to become a star.) Jupiter has a huge magnetic field, much stronger than Earth's. Its magnetosphere extends more than 650 million km (past the orbit of Saturn!). (Note that Jupiter's magnetosphere is far from spherical -- it extends "only" a few million kilometers in the direction toward the Sun.) Jupiter's moons therefore lie within its magnetosphere, a fact which may partially explain some of the activity on Io .

Unfortunately for future space travelers and of real concern to the designers of the Voyager and Galileo spacecraft, the environment near Jupiter contains high levels of energetic particles trapped by Jupiter's magnetic field. This "radiation" is similar to, but much more intense than, that found within Earth's Van Allen belts. It would be immediately fatal to an unprotected human being. The Galileo atmospheric probe discovered a new intense radiation belt between Jupiter's ring and the uppermost atmospheric layers. This new belt is approximately 10 times as strong as Earth's Van Allen radiation belts. Surprisingly, this new belt was also found to contain high energy helium ions of unknown origin. J upiter has rings like Saturn's, but much fainter and smaller (right). They were totally unexpected and were only discovered when two of the Voyager 1 scientists insisted that after traveling 1 billion km it was at least worth a quick look to see if any rings might be present. Everyone else thought that the chance of finding anything was nil, but there they were. It was a major coup. They have since been imaged in the infra-red from ground-based observatories and by Galileo . Unlike Saturn's, Jupiter's rings are dark ( albedo about .05).

They're probably composed of very small grains of rocky material. Unlike Saturn's rings, they seem to contain no ice. Particles in Jupiter's rings probably don't stay there for long (due to atmospheric and magnetic drag). The Galileo spacecraft found clear evidence that the rings are continuously resupplied by dust formed by micrometeor impacts on the four inner moons , which are very energetic because of Jupiter's large gravitational field. The inner halo ring is broadened by interactions with Jupiter's magnetic field. In July 1994, Comet Shoemaker-Levy 9 collided with Jupiter with spectacular results (left). The effects were clearly visible even with amateur telescopes. The debris from the collision was visible for nearly a year afterward with HST. When it is in the nighttime sky, Jupiter is often the brightest "star" in the sky (it is second only to Venus, which is seldom visible in a dark sky). The four Galilean moons are easily visible with binoculars; a few bands and the Great Red Spot can be seen with a small astronomical telescope. There are several Web sites that show the current position of Jupiter (and the other planets) in the sky. More detailed and customized charts can be created with a planetarium program .

Jupiter's Satellites Jupiter has 67 known satellites : the four large Galilean moons plus many more small ones some of which have not yet been named: Jupiter is very gradually slowing down due to the tidal drag produced by the Galilean satellites. Also, the same tidal forces are changing the orbits of the moons, very slowly forcing them farther from Jupiter. Io, Europa and Ganymede are locked together in a 1:2:4 orbital resonance and their orbits evolve together. Callisto is almost part of this as well. In a few hundred million years, Callisto will be locked in too, orbiting at exactly twice the period of Ganymede (eight times the period of Io). Jupiter's satellites are named for other figures in the life of Zeus (mostly his numerous lovers). Many more small moons have been discovered recently but have not as yet been officially confirmed or named. The most up to date info on them can be found at Scott Sheppard's site .

Distance Radius Mass Satellite (000 km) (km) (kg) Discoverer Date --------- -------- ------ ------- ---------- ----- Metis 128 20 9.56e16 Synnott 1979 Adrastea 129 10 1.91e16 Jewitt 1979 Amalthea 181 98 7.17e18 Barnard 1892 Thebe 222 50 7.77e17 Synnott 1979 Io 422 1815 8.94e22 Galileo 1610 Europa 671 1569 4.80e22 Galileo 1610 Ganymede 1070 2631 1.48e23 Galileo 1610 Callisto 1883 2400 1.08e23 Galileo 1610 Leda 11094 8 5.68e15 Kowal 19

74 Himalia 11480 93 9.56e18 Perrine 1904 Lysithea 11720 18 7.77e16 Nicholson 1938 Elara 11737 38 7.77e17 Perrine 1905 Ananke 21200 15 3.82e16 Nicholson 1951 Carme 22600 20 9.56e16 Nicholson 1938 Pasiphae 23500 25 1.91e17 Melotte 1908 Sinope 23700 18 7.77e16 Nicholson 1914 Values for the smaller moons are approximate.

Many more small moons are not listed here. Distance Width Mass Ring (km) (km) (kg) ---- -------- ----- ------ Halo 100000 22800 ? Main 122800 6400 1e13 Gossamer 129200 214200 ? (distance is from Jupiter's center to the ring's inner edge) More about Jupiter and its satellites Planets, the Solar System and beyond | Planetsedu.com Distances between planets: View matrix The eight planets are the dominant bodies in the Solar System after the Sun. Ancient peoples could identify the planets in the sky and saw them as emissaries of the gods. In 2006, the International Astronomical Union (IAU) recognised Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune as planets. A planet was defined as a celestial body that orbits the Sun. It must have enough mass for its self-gravity to surmount rigid body forces. In this way, it acquires a hydrostatic equilibrium, meaning that it has an almost round shape. In addition, it must have a clear path in its orbit around the Sun.

The planets are divided into two groups: terrestrial planets and gas giants. Terrestrial planets are those that are similar to Earth. In addition to the Earth, these planets are Mercury, Venus and Mars. They are mostly composed of rock and are sealed within a hard external crust. Denser material, such as iron and nickel, sinks into the centre – the core – of the planet. The interior of the planet becomes differentiated, or separated, into a molten core, a semi-plastic or liquid mantle and a hard, outer crust. Mercury is the smallest terrestrial planet and the smallest planet in the solar system. Earth is the largest terrestrial planet. The gas giants, or Jovians (named after the planet Jupiter), are composed of gaseous material. They are thought to have some rock at their core. Their mantles are composed of mostly iced water, ammonia and methane in various proportions. These planets are Jupiter, Saturn, Uranus and Neptune. Jupiter, which is 318 times the mass of the Earth, is the largest gaseous planet and the largest planet in the solar system. Uranus is the smallest gaseous planet. All of the planets have atmospheres. Mercury has the thinnest atmosphere.

Energy radiated from the Sun heats these atmospheres and creates weather systems such as storms and cyclones. The orbits of the planets around the Sun are nearly circular and in a thin disc. The eccentricity of an orbit is a measure of the elongation of this circular path into an elliptical shape. The planets revolve around their own axes. These axes lie at an angle – the axial tilt – to the Sun’s equator. Astronomy for Kids: The Planet Jupiter Distance from the Sun: 5th planet from the sun, 484 million miles What is Jupiter like? Jupiter is the largest planet in the Solar System and is the fifth planet from the sun. It is more than 300 times more massive than Earth and is more than two times as massive than all the other planets combined. Jupiter is called a gas giant planet. This is because its surface is made up of a thick layer of hydrogen gas . Deep within the planet, under the gas, the pressure becomes so intense that the hydrogen turns into liquid and then finally into a metal. Under the Hydrogen is a rocky core that is about the size of planet Earth.

Weather on Jupiter Jupiter's surface is very violent with massive hurricane -like storms, winds, thunder and lightning. One storm on Jupiter, called the Great Red Spot, is three times the size of earth. The Great Red Spot has been storming for hundreds of years. The energy powering Jupiter's storms isn't from the sun, but is from radiation generated by Jupiter itself. The Moons of Jupiter Jupiter is home to a number of interesting moons including Ganymede, Io, Europa, and Callisto. These four moons were first discovered by Galileo and are called the Galilean Moons. Ganymede, the largest moon in the Solar System, is larger than the planet Mercury. Io is covered in volcanoes and lava. Europa, on the other hand, is covered in ice and has a huge salt water sea underneath the ice. Some think there is a good possibility that life may exist in the seas of Europa. The many varying moons around Jupiter make it a fascinating place to explore. How does Jupiter compare to Earth? Jupiter is wildly different from Earth. First off, there is no place to stand, the surface is gas.

Second, Jupiter is 300 times the size of earth and has (at least) 63 moons vs. Earth's one moon. Also, Jupiter has a 300 year-old storm that would swallow up the Earth without even noticing it. I'm glad we don't have any storms like that! How do we know about Jupiter? Being the 4th brightest object in the sky, humans have known of Jupiter's existence for thousands of years. Galileo first discovered Jupiter's 4 largest moons in 1610 and others claim to have discovered the Great Red Spot not long after. In 1973 the space probe Pioneer 10 flew by Jupiter and provided the first close up pictures of the planet. The Pioneer probes were followed by Voyager 1 and 2 which gave us the first close up shots of Jupiter's moons. Since then there have been many more fly-bys of Jupiter. The only spacecraft to orbit Jupiter was the Galileo in 1995. Fun Facts about the Planet Jupiter In Roman mythology, Jupiter was king of the gods and god of the sky. He was the equivalent of the Greek god Zeus. It is the fastest spinning planet in the Solar System.

Jupiter has three very faint rings. It has an extremely strong magnetic field that is 14 times stronger than the magnetic field of the Earth. Viewed from the Earth, it is the third brightest object in the night sky. More Astronomy Subjects Mass of Jupiter - Universe Today Universe Today by Jerry Coffey The mass of Jupiter is 1.9 x 1027 kg. It is hard to fully understand a number that large, so here are a few comparisons to help. It would take 318 times Earth’s mass to equal Jupiter’s. Jupiter is 2.5 times more massive than all of the other planets in our Solar System combined. Jupiter is actually so massive that if it gained much more mass it would shrink. How can additional mass cause a planet to shrink? Gravitational compression. Given that there is no more hydrogen or helium gas floating around for Jupiter to collect, it would gain mass through the accretion of rocky bodies like asteroids. Jupiter’s intense gravity would pull additional rock tightly together shrinking the diameter of the planet and increasing its density. As the density increased so would the gravity, further compressing the planet.

Scientists estimate that Jupiter would have to accumulate 3-4 times its current mass in order to begin compressing. Since there isn’t that much material in our Solar System, it is a pretty good bet that Jupiter will never shrink. But what if it did? There have been rumors floating around for decades that Jupiter could ignite fusion and become a star at any time. They are all false science and garbage at best. The mass of Jupiter is no where near enough for sustained nuclear fusion. Fusion requires high temperatures, intense gravitational compression, and fuel. Jupiter has the right fuels in abundance. There is plenty of hydrogen to be had, but the planet is too cold and lacks the density for a sustained reaction process. Scientists estimate that Jupiter needs 50-80 times its current mass to ignite fusion. As stated in the paragraph above, there isn’t enough material to be had, so Jupiter can not become a star. At one time, scientists thought that Jupiter was the largest that a planet could become without igniting fusion and becoming a star. They discovered the fallacy of that belief once technology expanded their view of the universe. According to Dr.

Sean Raymond, a post doctoral researcher at the Center for Astrophysics and Space Astronomy (CASA) at the University of Colorado, ”In terms of gaseous planets, once they reach 15 Jupiter masses or so there is enough pressure in the core to ignite deuterium fusion, so those are considered ‘brown dwarfs’ rather than planets.” As you can see, the mass of Jupiter may seem awesome in comparison to Earth, it is a tiny fish in a world of sharks. Scientists have found a few hundred gas giants larger than Jupiter as they have surveyed the night sky. Who knows what is in store as telescope technology improves in the coming years. Here’s an article from Universe Today explaining just how big planets can get , and an article about how Jupiter and the other gas giants might have gobbled up their moons while they were forming. This site has more detailed information about the mass of Jupiter, and a page from NASA that helps you calculate the density of the planets. We’ve also recorded an entire show just on Jupiter for Astronomy Cast. Listen to it here, Episode 56: Jupiter , and Episode 57: Jupiter’s Moons .

Sources: Your Weight on Other Worlds | Exploratorium YOUR WEIGHT ON OTHER WORLDS Ever wonder what you might weigh on Mars or The Moon? Here's your chance to find out. TO DO & NOTICE: Fill in your weight below in the space indicated. You can enter your weight in any unit you wish. Click on the "Calculate" button. Notice that the weights on other worlds will automatically fill in. Notice that your weight is different on the different worlds. You can click on the images of the planets to get more information about them from Bill Arnett's incredible Nine Planets web site. ENTER YOUR WEIGHT HERE → A Few Different Types of Stars (better land at night to avoid burning your feet!) THE SUN WHAT'S GOING ON? Mass and Weight Before we get into the subject of gravity and how it acts, it's important to understand the difference between weight and mass. We often use the terms "mass" and "weight" interchangeably in our daily speech, but to an astronomer or a physicist they are completely different things. The mass of a body is a measure of how much matter it contains. An object with mass has a quality called inertia.

If you shake an object like a stone in your hand, you would notice that it takes a push to get it moving, and another push to stop it again. If the stone is at rest, it wants to remain at rest. Once you've got it moving, it wants to stay moving. This quality or "sluggishness" of matter is its inertia. Mass is a measure of how much inertia an object displays. Weight is an entirely different thing. Every object in the universe with mass attracts every other object with mass. The amount of attraction depends on the size of the masses and how far apart they are. For everyday-sized objects, this gravitational pull is vanishingly small, but the pull between a very large object, like the Earth, and another object, like you, can be easily measured. How? All you have to do is stand on a scale! Scales measure the force of attraction between you and the Earth. This force of attraction between you and the Earth (or any other planet) is called your weight. If you are in a spaceship far between the stars and you put a scale underneath you, the scale would read zero. Your weight is zero. You are weightless. There is an anvil floating next to you.

It's also weightless. Are you or the anvil mass-less? Absolutely not. If you grabbed the anvil and tried to shake it, you would have to push it to get it going and pull it to get it to stop. It still has inertia, and hence mass, yet it has no weight. See the difference? The Relationship Between Gravity and Mass and Distance As stated above, your weight is a measure of the pull of gravity between you and the body you are standing on. This force of gravity depends on a few things. First, it depends on your mass and the mass of the planet you are standing on. If you double your mass, gravity pulls on you twice as hard. If the planet you are standing on is twice as massive, gravity also pulls on you twice as hard. On the other hand, the farther you are from the center of the planet, the weaker the pull between the planet and your body. The force gets weaker quite rapidly. If you double your distance from the planet, the force is one-fourth. If you triple your separation, the force drops to one-ninth. Ten times the distance, one-hundredth the force. See the pattern? The force drops off with the square of the distance.

If we put this into an equation it would look like this: The two "M's" on top are your mass and the planet's mass. The "r" below is the distance from the center of the planet. The masses are in the numerator because the force gets bigger if they get bigger. The distance is in the denominator because the force gets smaller when the distance gets bigger. Note that the force never becomes zero no matter how far you travel. Perhaps this was the inspiration for the poem by Francis Thompson: All things That thou cans't not stir a flower without troubling a star. Isaac Newton This equation, first derived by Sir Isaac Newton, tells us a lot. For instance, you may suspect that because Jupiter is 318 times as massive as the Earth, you should weigh 318 times what you weigh at home. This would be true if Jupiter was the same size as the Earth. But, Jupiter is 11 times the radius of the Earth, so you are 11 times further from the center. This reduces the pull by a factor of 112 resulting in about 2.53 times the pull of Earth on you. Standing on a neutron star makes you unimaginably weighty.

Not only is the star very massive to start with (about the same as the Sun), but it is also incredibly small (about the size of San Francisco), so you are very close to the center and r is a very small number. Small numbers in the denominator of a fraction lead to very large results! NASA's Prolific Planet Hunter: Kepler Telescope By-The-Numbers NASA's Prolific Planet Hunter: Kepler Telescope By-The-Numbers By Tariq Malik, Space.com Managing Editor | February 2, 2011 05:56pm ET MORE An artist's interpretation of NASA's planet-hunting Kepler observatory in space. Credit: NASA. NASA's Kepler space observatory has found more than 1,200 potential alien worlds since it began hunting for extrasolar planets in 2009. Observations from the mission's first four months alone have unlocked a flood of exoplanet possibilities, including 54 candidates for habitable worlds orbiting distant stars. Today (Feb. 2) NASA unveiled the latest set of observations from that four-month period.

NASA officials expect the $600 million Kepler observatory to continue staring at its target patch of sky until at least November 2012. Here's a by-the-numbers look at NASA's planet-hunting Kepler mission and its alien world discoveries, as of Feb. 2, 2011: $600 million: The cost of the Kepler planet-hunting mission at its launch in March 2009. 156,000: The number of stars in the constellations Lyra and Cygnus that the Kepler observatory is staring at 24 hours a day, seven days a week, in the search for extrasolar planets. Kepler's field of views covers about 1/400th of the sky. 1,235: The number of potential alien planets that Kepler has discovered. NASA has repeatedly cautioned that all of Kepler's findings must be confirmed by follow-up observations using other space and ground telescopes. 662: The number of planet candidates found by Kepler that would be about the size of Neptune.

Neptune has a radius of about 15,388 miles (24,764 km) wide and has a mass that is 17 times that of the Earth, according to NASA. 288: The number of exoplanet candidates discovered by Kepler that are in the super-Earth class. Super-Earths are planets with masses between two and 10 times the mass of Earth, according to NASA. 170: The number of stars that seem to have more than one planetary candidate orbiting them – which would make them parts of alien solar systems . 165: The number of potential planets found to be the size of Jupiter, which is the largest planet in our solar system. Jupiter has a radius of about 44,423 miles (71,492 km) and has a mass that is 318 times that of the Earth. 68: The number of Earth-size planet candidates in the Kepler data release. 54: The number of the planet candidates that appear to be in the "habitable zone" around their parent stars.

The habitable zone is a belt just far enough from the star for any orbiting planet to be able to have liquid water on its surface. More on the Habitable Zone planets from Kepler: Of the 54 potentially habitable planets found by Kepler, only five are about the size of Earth, NASA officials said. The other 49 have sizes that range between the classes of super-Earths (twice the size of Earth) and jumbo Jupiters. 19: The number of potential alien planets larger than Jupiter. 15: The number of planets discovered by Kepler that have been confirmed to exist by follow-up observations by astronomers using other instruments. 4: The number of months Kepler spent searching for extrasolar planets for the data set used to compile the statistics above. The space telescope was gazing at the same patch of sky from May 12, 2009 to Sept. 17 of that same year. 1: The number of Earth-size and Earthlike habitable planets confirmed to exist with intelligent life. We call this planet Earth. You can follow SPACE.com Managing Editor Tariq Malik on Twitter @tariqjmalik . Editor's Recommendations

Question: Which planet in the solar system has a mass which is 318 times that of the earth?
Answer: JUPITER